Soprano Julia Bullock has the kind of voice that immediately captivates. It has an enthralling combination of power and pathos. The result is a highly expressive and intangible human empathy that Bullock will undoubtedly bring to the Lyric Theatre stage on Monday. A proven interpreter of contemporary classical music, Bullock has had a pivotal role in the performance of works by such illustrious living composers as John Adams and Kaija Saariaho. But the Eastman School of Music alumna is also at home with the repertoire of Purcell, Mozart, Ravel, and Schubert.